Starting unloader



Nov. 16,1926. 1,607,531., H. V. HAIGHT STARTING UNLOADER Filed July 27, 1926 IN VEN TOR.

fiddly I IIQIL 12! BY .a/

HIS ATT NEY Patented Nov; 16, 1926.

.HARRY v. HAIGHT, on SHEBZBROOK'E, QUEBEC,

1,607,531- PATENT "OFFICE.

CANADA, ASSIGNOB TO INGERSOLL- RAND COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

Application filed July 27.

This invention relates to unloaders for compressors, but more particularly to' a starting unloader for compound compressors in which any of the well known step by step automatic unloading devices as they are called may be employed as usual. In addition, the features of my starting unloader may be applied, so that the'compressor is unloaded on starting up, shutting down or standing, but is automatically loaded when the motor comesup to speed. Furthermore the water for the water jacket may be automatically controlled by a water valve connected in the unloading system. 1

The invention is particularly applicable to an electric driven compressor having a magnetic starting unloading device which maybe of any suitable or usual type on the market, so constructed that the electromagnet of the device is only energized when a field contactor on the motor is closed, after the motor comes up to speed.

The objects of the invention are to simplify the construction and operation of a pressure actuated starting unloader which may or may not be controlled by a magnetic device, but has some suitable master valve, which may be called a change valve, automatically controlling all the unloading valves or devices of the compressor. I prefer to employ cylinder relief valves for the high pressure cylinder in addition to the clearance valves or other unloading devices of the compressor, and, I also employ an intercooler unloader. In the preferred construction one change valve controls the automatic step by step unloading'mechanism of the compressor, the high pressure cylinder relief valves, the intercooler unloader, and

40 the water valve if a water valve is used.

The change valve is preferably responsive to the discharge ressure of the high pressure cylinder and if a magnetic unloading device is used, such magnetic device is connected to control the change valve, by regulating the application of high pressure discharge pressurejo said change valve for actuating the valve.

The invention is illustrated in the accompanying drawing, which is a diagrammatic representation, partly 1n vertlcal sect1on, of a compound compressor having my starting unloader applied thereto.

In this instance the automatic step by step unloading system in general islike that s'ranrnve UNLOADEB.

1926. Serial No. 125,242,

shown in United States Patent N 0. 1,430,578 granted October 3, 1922 to C. W. Metzgar, ass gnor to Ingersoll-Rand Company, in which the high and low pressure cylinders A and B are provided with clearance valves a controlling clearance chambers (not shown) and the ,valvesc are adapted to be connected by pipes 1, 2, 3 and 4 with correspondingly numbered pipes 1, 2, 3 and 4 on the regulator X, and ressure fluid from the receiver D is led to t e regulator X through thepipe H connected at J to the regulator casing Q. The clearanceva'lves may preferably be of the type held closed by pressure fluid and adapted to be opened by springs as in said patent. As inthe usual regulators of this type, a diaphragm (not shown) in the casing Q is responsive to receiver pressure and a pin S adapted to be actuated by the diaphragm bears underneath a weighted lever B, pivoted at T to the casing Q. An auxiliary or pilot valve 30 operating in the valve casing 32 is hun from the lever B at the point 31 and is a apted to successively control the su ply and exhaust of pressure fluid to and from the pipes 1, 2, 3 and 4 leading ,to the clearance valves 0 so that the compressor is unloaded and loaded in steps according to the needs of the system. Reference may be had to said Patent No. 1,430,57 8 for the details of this part of the construction, which is here shown only diagrammatically in order to illustrate a well known type of compressor and unloading mechanism therefor to which my invention may be applied.

.The cylinders 'A and B have an intercooler C interposed between them and the discharge pipe from the high pressure cylinder is connected as shown to the receiver D. A" constant speed electric motor G'is suitably connected to drive the compressor and this motor is assumed to be provided with .a

'field contactor (not shown) connected by the leads a and b with the magnetic unloading device F of any suitable or usual type having an electromagnet d and a core or armature 6 connected to rock a lever f about its pivot g on the casing h. This casing forms a valve chamber within which are located the ball valves j and 7c controlling the pipes 5 and 6 andthe atmospheric vent 7. The mechanical construction of the magnetic'unloader is simple and will be readily understood from an inspection ofthe drawing. 11o

When starting, shutting down or standing the compressor is unloaded, and at these times the magnetic unloader is deenergized, so that the core or armature e is in its lowermost position and is only retracted when the magnet d is energized after the motor comes up to speed. When the core e is down as indicated in the figure, the pipe 5 is connected to the pipe 6 and the vent 7 is closed. When the magnet is energized and the core is retracted, the pipe 5 is shut off or closed by the valve 7' and the vent 7 is opened by V the valve 70, so that pipe 6 is exhausted to atmosphere.

The magnetic unloader F regulates and controls the operation of a change valve L which constitutes a single master valve or mechanism which in turn controls the regulator X, the intercooler unloader O, the high pressure cylinder relief valves P, and if desired the water valve T or any other desired accessory mechanism.

The change valve is preferably actuated by pressure fluid from the high pressure cylinder B ledby the pipe 5 from the point 8 in the discharge passage of the cylinder P to the magnetic unloader F and from thence by pipe 6 to the change valve diaphragm 0, by means of which the spring pressed ball valve p is actuated. The pipe sis also connected at the point 9 to the change valve casingover the valve 7). When the motor G comes up to speed and pressure in the lower pipe 6 is exhausted to atmosphere through the vent 7 of the magnetic unloader F, the ball valve 10 of the change valve L seats downwardly, instead of upwardly, as indicated in the drawing in its normal unloading position. With the parts as shown in the drawing, the main controlling pipe 10 of the change valve is vented to atmosphere through the vent pipe 12, and as the pipe 10 connects by means of its various branches 13, 14 15 and 16 with the regulator X, intercooler unloader relief valves P and water valve T, respectively, all these devices are simultaneously controlled by the change valve L,

The intercooler unloader 0 contains a valve g adapted to be subjected at one end 1 to pressure fluid from the pipe 14 and controlling the atmospheric vent 17 by means of which the intercooler is unloaded.

The cylinder relief valves 1 are alike and are connected to each end of the high pres sure cylinder 18. Each has a diaphragm a actuating a valve a controlling communication between the cylinder and the atmospherig vent 18.

The Water valve T has the spring pressed poppet valve actuated by the diaphragm o and controlling the flow of jacket water through the pipes. V

lln theoperation, of the apparatus, and assuming that the compressor is starting up,

the parts will at first be in the positions indicated, that is, the magnetic unloader F is deenergized, and the core 6 is in its lowermost position so that the pipes 5 and 6 are in communication and the vent 7 is closed. Consequently the pressure fluid from the high pressure cylinder B flows through pipes 5 and 6 to the diaphragm 0 of the change valve, holding the ball valve 1) upwardly, closing the port from pipe 5 in the upper part of the change valve casing and venting the main controlling pipe 10 to atmosphere at the vent 12. Thus all the controlling devices are vented to atmosphere.

Pressure fluid flows from all the clearance valves 0 through pipes 1, 2, 3 and 4 and the pipe 13 to the change valve, so that pressure is released from all the clearance valves and they are allowed to open and unload the cylinders A and B. Pressure is also released behind the intercooler unloader Q through pipe 14, and beneath the cylinder relief valves P through pipe 15, and from above the water valve T through the pipe 16, so that the intercooler unloader and the relief valves open'and the water valve closes. The unloading of the intercooler more completely unloads the low pressure cylinder.

When the motor comes up to full speed and .the field contactor closes, assumed to be provided on the motor (but not shown), all the above conditions are reversed, because the magnet d becomes energized and lifts its core 6, thus opening the vent 7 which permits the change valve L to reverse its position and close the vent 12. Pressure fluid then passes from pipe 5 at the top of the change valve, to all the pipes 10, 13, 14, 15 and 16, thereby closing the intercooler unloader O and the relief valves P, and opening the water valve T. The regulator X then functions in the usual way while the compressor is running.

ll claim:

1. A. starting unloader for compressors, comprising multiple cylinders and an intercooler, unloading mechanism for the c linders, additional relief valves for the -igh pressure cylinder, an intercooler unloader, and a change valve controlling said cylinder unloading mechanism, relief valves and intercooler unloader.

2. A starting unloader for compressors, comprising multiple cylinders and an intercooler, unloading mechanism for the cylinders, additional relief valves for the highpressure cylinder, an intercooler unloader, change valve controlling said cylinder unloading mechanism, relief valves and intercooler unloader, and means for controlling said change valve.

3. A. starting unloader for compressors, comprising multiple cylinders and an intercooler, unloading mechanism tor the cvlinders, additional relief valves for the high comprising multiple cylinders and pressure cylinder, an, intercooler unloader, and a change valve responsive to the discharge pressure of the high pressure cylinder for controlling said cylinder unloading mechanism, relief valves and intercooler unloader.

4. A starting unloader for compressors,

an intercooler, unloading mechanism for the cylinders, additional relief valves for the high pressure cylinder, an intercooler unloader, a change valve responsive to the discharge pressure of the high pressure cylinder for controlling said cylinder unloading mechanism, relief valves and intercooler unloader, and means for controlling the application of high pressure discharge pressure to said change valve for actuating the valve.

5. A starting unloader for compressors, comprising multiple cylinders and an intercooler, unloading mechanism. for the cylinders, additional relief valves for the high pressure cylinder, an intercooler unloader, a water valve, and a change valve controlling said cylinder unloading mechanism, relief valves, intercooler unloader and water valve.

In testimony whereof I have signed this specification.

HARRY V. HAIGHT. 

